The diagnosis of osteomyelitis in patients with pressure sores.

A prospective blind trial was undertaken to assess the usefulness of commonly used tests to diagnose osteomyelitis underlying pressure sores. Sixty-one pressure sores were studied, with a histopathologic diagnosis from the ostectomy specimen being available in 52. White cell count, erythrocyte sedimentation rate, plain pelvic x-ray, technetium-99m bone scan, computerized tomography, and Jamshidi needle bone biopsy were studied. The most useful individual test was a needle bone biopsy, with a sensitivity of 73 percent and a specificity of 96 percent. Technetium-99m bone scans and computerized tomography are not indicated in the diagnosis of osteomyelitis associated with pressure sores. Plain pelvic x-ray, white cell count, and erythrocyte sedimentation rate, with a diagnosis of osteomyelitis if any test is positive, is the most sensitive (89 percent), specific (88 percent), noninvasive workup. Jamshidi needle biopsy may be useful where these tests are negative and a clinical suspicion of osteomyelitis remains. Extent of surgical debridement and antibiotic therapy can then be rationally decided on the basis of this information.